Chain guard



FIG. 1 is a perspective of a chain guard embodying my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a side elevational view as seen from the right side; and,

FIG. 7 is a side elevation view as seen from the left side. 

The ornamental design for a chain guard, as shown. 